Television receiver sets



March 4, 1969 J. M. LIZARRALDE TELEVISION RECEIVER SETS Sheet of 2 Filed Jan. 4, 1967 Illllllltl l 5 March 4, 1969 J. M. LIZARRALDE TELEVISION RECEIVER SETS Sheet 2 of 2 Filed Jan. 4, 1967 United States Patent 3,431,463 TELEVISION RECEIVER SETS Jose M. Lizarralde, 67th St., N0. 786, Buenos Aires, Argentina Filed Jan. 4, 1967, Ser. No. 607,221 US. Cl. 315127 Int. Cl. Hb 41/36 4 Claims ABSTRACT OF THE DISCLOSURE The present invention relates to improvements in television receiver sets.

Conventional TV receiver sets known up to the present have a serious drawback consisting in the gradual decay of the centre zone of the phosphoric coating that covers the screen of the image tube, to which remains focused the beam of electrons emitted, caused by the thermal inertia of the tube filament when the electric supply to the coils of the deflecting yoke is cut off, i.e., when the TV set is turned off.

To this end, the main and basic object of this invention consists in obtaining a very simple arrangement of means for avoiding the impingement of the electron beam on said phosphoric coating, preventing the propagation of said beam from the electron gun of the tube towards the screen when the receiver set is turned on, in such a manner that it is not necessary to modify or rearrange the circuit or normal arrangement of the different elements of the set, but simply by adding to the set a device which does not even require modification of any common connection between said elements, which device can be applied to any type of TV set even those having very different characteristics and deviating widely from conventional constructions.

In other words, the aim is to obtain a very simple and practical device of general application to any type of TV receiver set, in order to prevent the propagation of the electron beam beyond the electron gun When the supply to the coils of the deflection yokes ceases, in order to avoid its impingement on the phosphoric coating of the screen, and consequently the destruction of its centre zone.

A very important object of this invention consists in that the referred device can be utilized with any type of receiver set and can be connected simply by interposing it between two common elements that are easily accessible in all sets, not requiring any modification in the conventional construction of the set.

All these objects and others that will appear hereinafter are embodied in the improvements invented. In order to facilitate the understanding and description of the invention, the device including the referred improvements has been illustrated in several figures, being:

FIGURE 1, a perspective view of the device.

FIGURE 2, a schematic view showing the electric circuit of said device and its connection to the image tube of the TV receiver set.

FIGURE 3, an elevation view and longitudinal section II of the device.

FIGURE 4, a top plan view.

FIGURE 5, the same view of FIGURE 3 showing a first alternative arrangement of the device.

Basically, the improvements invented consist in the following:

In every TV receiver set, the image tube or iconoscope a has in the outside surface of its glass bell 1, and anode 2 or contact for connecting to the very high voltage supply source.

According to the referred improvements, said anode 2 of the image tube a is tapped to a ground connection b controlled by means of a circuit breaker c interposed in said connection, which breaker is maintained in the closed position by gravity force, thus making the connection to ground, and is operated by electromagnetic means d to the open position, antagonically to the gravity force, thus disconnecting from ground. Said electromagnetic means include a coil 3 connected to same supply source provided for the filaments of the receiver circuit, a transformer I, in such a manner that the operation of said coil and consequently the action of the breaker are controlled by the main breaker B operated by the user for turning the receiver set on and off.

The referred breaker C basically consists of a movable contractor element c and a fixed corresponding contact 0'', first of which is mounted on a first arm 4 of a two-arm lever which can swing angularly around an axle 5 that is in a perfect horizontal position, in order to ensure that the force of gravity actuates freely and effectively on said movable contactor element 0'.

Said axle 5 is mounted on two supports 6 located in a wing 7 of the U-shaped chassis or frame e, each at a side of an ample rectangular opening 7, through which extends a second arm 8 of said lever in which is mounted the movable contactor element 0, that ends in a ferromagnetic plate 9 located inside the chassis and above the top end of a core 10' placed inside the referred coil 3. The supporting spool 11 of said coil is mounted on the inner surface of the other wing 12 of said chassis e; the referred lever arm 4 where the movable contactor element 0" is mounted is made of an electrical insulating material of very good quality. Said element 0' is formed by two contact tips 13 widely spaced from each other, mechanically secured to said arm 4, projecting from its inner surface and electrically connected together by an intermediate conductor 14. These two contactor tips 13 are mounted along the referred arm, one next to its end and the other approximately in its central position.

The wing 7 of the referred chassis e has a long extension 15 located just below the referred lever arm 4 that carries the movable contactor element 0', made of an electrical insulating material of very high quality, that carries the fixed contact c" of breaker 0 corresponding to the contactor tips 13, constituted like these, by two tips 16 and 17 mechanically secured to said extension 15 of chassis e. The first one is electrically connected to the anode 2 of image tube a, and the second 17 directly connected to ground, for instance by means of a conductor 18 to said wing 7 of chassis e which is made of a conducting material and is directly secured to the chassis of the receiver set.

A double set of contacts is used in breaker c in order to reduce as much as possible the sparking of an are when the movable contactor element 0 moves towards the closed position.

The utilization of a highly insulated cable is provided for the connection between the anode 2 of the image tube and the contactor tip 16 of breaker c. Two series connected resistors f are also included in this connection in order to reduce the circulation of current to a low value and prevent damage of the elements forming the circuit of the receiver set, in the filaments is closed, i.e., when the receiver set is turned on, in which event anode 2 would be subject to a very high voltage while being connected to ground through breaker c.

In order to ensure the movement of element c to the open position by gravity force, the lever arm 8 is made of heavier weight than the other arm 4 in which is mounted the movable contactor element c.

In order to ensure that the arm lever 4 with the movable contact element a rises disconnecting the anode from ground when the coil 3 is energized; since arm 4 is of heavier weight than arm 8 there is provided an arrangement shown in FIGURE 5, according to this arrangement, the axle 5 of said lever has a radial arm 19 extending above arm 8 with a threaded end 19' Where is applied a counterweight 20 formed by a nut for instance secured in position by a lock nut 21. This arrangement allows regulation of the unbalancing countertorque exerted by the weight of said arm lever 8 against the arm lever 4 in order to ensure that the difference of torque between both arms 4 and 8 will not exceed the effect of force of attraction of coil 3.

When the receiver set is turned ofi', anode 2 of image tube a is permanently connected to ground through the referred connection I) by means of the electric bridge that the movable contactor element 0 of breaker 0 establishes between both fixed contacts 16 and 17 of this breaker since the lever arm 4 supporting said contactor element 0 is down by the force of gravity.

When the receiver set is turned on and consequently the supply source for the filaments is energized, coil 3 is also energized and the movable contactor element 0 is abruptly moved to the open position by angular displacement of lever arm 4, due to the attraction of the ferromagnetic plate 9 in the other arm 8 of same lever by the core 10 of said coil 3, thus disconnecting anode 2 from ground, whereby the receiver set operates as usual.

When the receiver set is turned oif and consequently the filaments are deenergized, coil 3 is also deenergized and consequently frees lever arm 4 that carries the contactor element 0 of breaker c, which by gravity force alone lowers to the closed position reestablishing the electric bridge between both fixed contacts 16 and 17 of the breaker, thus reconnecting anode 2 of the image tube to ground.

Although the emission of electrons by thermal inertia of the tube filament is not avoided with the grounding of anode 2, an abrupt discharge of the electric potential built up in the tube is produced, that prevents the propagation of the electron beam beyond the tube gun, which consequently does not reach the phosphoric coating of the screen.

In order to adjust the position of the referred core 10 of coil 3 relative to the ferromagnetic plate 9 of the second arm of lever 8, said core is axially adjustable within the coil spool 11, screwed inside same or resting, through the end opposite to the one facing said plane, on a screw which serves for said adjustment.

No doubt that in the embodiments of this invention, some modifications can be introduced in details of construction or particulars of the improvements invented,

but never departing from the fundamental principles clearly set forth in the following claims.

I claim:

1. Improvements in television receiver sets, characterized because the anode of the image tube to which the supply source of very high voltage is connected is tapped to a ground connection controlled by a circuit breaker having a movable contactor element that establishes an electric bridge between a first contact connected to said anode of the image tube and a second contact connected to ground, said movable contactor element being actuated to a closed position by gravity force connecting the referred anode of the image tube to ground, said movable contactor element being related to electromagnetic means, capable of moving said movable contactor element to an open position antagonically to the gravity force and to keep it in said position while said means are connected to a source of electric supply, said means including a core connected to the supply source for the filaments in the circuit of the receiver set and controlled by the breaker of this circuit, including at least one resistor interposed between said anode of the image tube and the first fixed contact of said grounding breaker.

2. Improvements in television receiver sets, according to the preceding claim, characterized because said movable contactor element is mounted angularly swingable around an horizontal axle.

3. Improvements in television receiver sets, according to claim 1, characterized because said movable contactor element is mounted on a first arm of a lever made of insulating material and has two contact tips widely spaced from each other, mechanically secured to said arm and electrically connected together by an intermediate conductor, the second arm of said lever having at least one ferromagnetic portion placed within the field of attraction of one of the poles of a metal core located inside said coil that forms part of the electromagnetic means that actuates the breaker to the open position.

4. Improvements in television receiver sets, according to claim 3, characterized because the first lever is heavier than the second arm lever, said lever fixed to an axle, from which projects a radial arm with a threaded end where a counterweight is applied in order to regulate the unbalancing torque effort of said second arm against the torque exerted by the first arm lever.

References Cited UNITED STATES PATENTS 2,254,214 9/1941 Gage 317-17 XR 2,523,406 9/1950 Wilder 315-1 XR 2,619,525 11/1952 Webb 315-17 XR JOHN W. HUCKERT, Primary Examiner.

J. R. SHEWMAKER, Assistant Examiner.

US. Cl. X.R. 

